allow handle in shadowRoot

[christophe-g]

Closes #487

Adaptations required to allow handle in shadowRoot:

• Event re-targeting (https://gist.github.com/praveenpuglia/0832da687ed5a5d7a0907046c9ef1813#events-in-shadow-dom) : event.target might not be the real initial event target, hence the getEventTarget method.
• document-fragment does not have a parentElement (https://gist.github.com/praveenpuglia/0832da687ed5a5d7a0907046c9ef1813#terminologies), hence the use of event.composedPath() in findSortable instead of looping up dom tree to find sortable.

Tests are passing, no time not to write new test for this feature.

In case you are interested, I can PR a Polymer 2.0 port (actually rewrite) of https://github.com/rodrigosancho/polymer-html5sortable that would contain a demo testing this new feature.

[coveralls]

Coverage decreased (-1.06%) to 6.944% when pulling 804ef8b on christophe-g:support-shadowroot-handlers into 872e0ce on lukasoppermann:master.

[lukasoppermann]

Hey, yes please send a polymer 2 port. 👍

[christophe-g]

Hey, yes please send a polymer 2 port.

Cool, I'll do that early next week.

[lukasoppermann]

Hey, can you do me a favor and remove all compiled files from the PR? So send only the ones in src. I thought I could delete them from the PR but this is actually saying a "delete this file".

Thanks.

[christophe-g]

@lukasoppermann - sure.

Should build files not be git-ignored ?

[lukasoppermann]

Thanks.

Well the issue with .gitignore is that I need to be able to push those file to master when doing a new release.

I know of no way to ignore files but let me push them to master. 😞

[christophe-g]

@lukasoppermann - understood.

I am not an npm expert, but I think you can whitelist files that need to be included in the release package by adding :

“files”: [“build/**/*”]

in package.json, and still let git ignore them (https://itnext.io/step-by-step-building-and-publishing-an-npm-typescript-package-44fe7164964c)

[lukasoppermann]

Ahh, so you are saying never push them to master but add them to npm? I'll investigate that. 👍

[lukasoppermann]

Hey @christophe-g could you update the PR so I can merge it? Thanks.